1. Field of the Invention
The present invention relates to a wired circuit board and a producing method thereof, and particularly to a wired circuit board used appropriately for a suspension board with circuit which is mounted in a hard disk drive and a producing method thereof.
2. Description of the Related Art
A suspension board with circuit includes a metal supporting board, an insulating base layer formed thereon, and a conductive layer formed thereon and having head-side terminals for connecting to a magnetic head. On the suspension board with circuit, the magnetic head is mounted and connected to the head-side terminals. With the metal supporting board being supported on a load beam, the suspension board with circuit is mounted in a hard disk drive.
In recent years, it has been examined to connect such a suspension board with circuit to various electronic elements such as, e.g., a piezo element (piezoelectric element) and accurately and finely adjust the position and angle of a magnetic head. Since such an electronic element has relatively low heat resistance, it is necessary to electrically connect the electronic element to electronic-element-side terminals (terminals formed on a conductive layer and different from head-side terminals) at a relatively low temperature via a conductive adhesive or the like.
Low-temperature connection provided between the electronic element having low heat resistance and the electronic-side terminals via the conductive adhesive is lower in the strength of connection between the conductive adhesive and the electronic-side terminals than high-temperature connection provided therebetween via a molten solder. Accordingly, it has been required to sufficiently improve such connection strength.
To satisfy the requirement, it has been proposed to provide grooves (through grooves) in a circular 1 and along a circumferential direction thereof, which are formed to extend through the circular 1 and in a thickness direction thereof (see, e.g., Japanese Unexamined Patent No. 2010-251619). In the wired board described in Japanese Unexamined Patent No. 2010-251619, a conductive paste is in contact with the upper surface of the 1 and, while filling the grooves. Since the upper surface of the land and the inner side surfaces of the grooves are in contact with the conductive paste, the land has an increased contact area with the conductive paste and improved adhesion thereto.